/* Copyright (C) 2004 - 2006  db4objects Inc.  http://www.db4o.com

This file is part of the db4o open source object database.

db4o is free software; you can redistribute it and/or modify it under
the terms of version 2 of the GNU General Public License as published
by the Free Software Foundation and as clarified by db4objects' GPL 
interpretation policy, available at
http://www.db4o.com/about/company/legalpolicies/gplinterpretation/
Alternatively you can write to db4objects, Inc., 1900 S Norfolk Street,
Suite 350, San Mateo, CA 94403, USA.

db4o is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA  02111-1307, USA. */
namespace Db4objects.Db4o.Internal.CS.Messages
{
	public sealed class MQueryExecute : Db4objects.Db4o.Internal.CS.Messages.MsgQuery
	{
		private Db4objects.Db4o.Config.QueryEvaluationMode _evaluationMode;

		public override bool ProcessAtServer(Db4objects.Db4o.Internal.CS.ServerMessageDispatcher
			 serverThread)
		{
			Unmarshall(_payLoad._offset);
			WriteQueryResult(Execute(), serverThread, _evaluationMode);
			return true;
		}

		private Db4objects.Db4o.Internal.Query.Result.AbstractQueryResult Execute()
		{
			lock (StreamLock())
			{
				Db4objects.Db4o.Internal.Query.Processor.QQuery query = (Db4objects.Db4o.Internal.Query.Processor.QQuery
					)Stream().Unmarshall(_payLoad);
				query.Unmarshall(Transaction());
				_evaluationMode = query.EvaluationMode();
				return ExecuteFully(query);
			}
		}

		private Db4objects.Db4o.Internal.Query.Result.AbstractQueryResult ExecuteFully(Db4objects.Db4o.Internal.Query.Processor.QQuery
			 query)
		{
			try
			{
				Db4objects.Db4o.Internal.Query.Result.AbstractQueryResult qr = NewQueryResult(query
					.EvaluationMode());
				qr.LoadFromQuery(query);
				return qr;
			}
			catch
			{
				return NewQueryResult(query.EvaluationMode());
			}
		}
	}
}
